Dakota 2WD V8-4.7L VIN J (2005)
Odometer: Description and Operation
An odometer and trip odometer are standard equipment in all instrument clusters. The odometer, trip odometer, and engine hours information are
displayed in a common electronic, blue-green Vacuum-Fluorescent Display (VFD) unit. This VFD unit is soldered onto the cluster electronic circuit
board and is visible through a window with a smoked clear lens located below the tachometer in the lower right area of the cluster overlay. The dark lens
over the VFD prevents the indicator from being clearly visible when it is not illuminated.
The odometer, trip odometer, and engine hours information are not displayed simultaneously. The trip odometer reset switch on the instrument cluster
circuit board toggles the display between odometer and trip odometer modes by depressing the odometer/trip odometer switch button that extends
through the lower edge of the cluster lens, just left of the minor gauge set. When the trip odometer information is displayed, the word "TRIP" is also
illuminated in the lower right corner of the odometer/trip odometer VFD in a blue-green color and at the same lighting level as the trip odometer
information. The engine hours information replaces the selected odometer or trip odometer information whenever the ignition switch is in the On
position and the engine is not running.
The odometer, trip odometer, and engine hours information is stored in the instrument cluster memory. This information can be increased when the
proper inputs are provided to the instrument cluster, but the information cannot be decreased. The odometer can display values up to 999,999
kilometers (999,999 miles). The odometer latches at these values, and will not roll over to zero. The trip odometer can display values up to 999.9
kilometers (999.9 miles) before it rolls over to zero. Engine hours are displayed in the format, "hr9999". The cluster will accumulate values up to 9,999
hours before the display rolls over to zero.
The odometer display does not have a decimal point and will not show values less than a full unit (kilometer or mile), while the trip odometer display
does have a decimal point and will show tenths of a unit (kilometer or mile). The unit of measure (kilometers or miles) for the odometer and trip
odometer display is not shown in the VFD. The unit of measure for the instrument cluster odometer/trip odometer is selected at the time that it is
manufactured, and cannot be changed. The odometer also has a "Rental Car" mode, which will illuminate the odometer information in the VFD
whenever the driver side front door is opened with the ignition switch in the Off or Accessory positions.
During daylight hours (exterior lamps are Off) the odometer VFD is illuminated at full brightness for clear visibility. At night (exterior lamps are On),
the VFD lighting level is adjusted with the other cluster illumination lamps using the panel lamps dimmer thumbwheel on the headlamp switch. However,
a "Parade" mode position of the panel lamps dimmer thumbwheel allows the VFD to be illuminated at full brightness if the exterior lamps are turned On
during daylight hours.
The odometer/trip odometer VFD, the trip odometer switch, and the trip odometer switch button are serviced as a unit with the instrument cluster.
The odometer and trip odometer give an indication to the vehicle operator of the distance the vehicle has traveled. The engine hours give an indication of
the cumulative engine-on time. This indicator is controlled by the instrument cluster circuitry based upon cluster programming and electronic messages
received by the cluster from the Powertrain Control Module (PCM) over the Controller Area Network (CAN) data bus.
The odometer, trip odometer and engine hours information is displayed by the instrument cluster odometer/trip odometer Vacuum Fluorescent Display
(VFD). The VFD will display the odometer information whenever any door is
opened with the ignition switch in the Off or Accessory positions, and will display the last previously selected odometer or trip odometer information
when the ignition switch is turned to the On or Start positions. The instrument cluster circuitry controls the VFD and provides the following features:
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Odometer/Trip Odometer Display Toggling - Actuating the trip odometer reset switch button momentarily with the VFD illuminated will toggle
the display between the odometer and trip odometer information. Each time the VFD is illuminated with the ignition switch in the On or Start
positions, the display will automatically return to the last mode previously selected (odometer or trip odometer).
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Engine Hours Display Toggling - When the trip odometer reset switch button is pressed and held for longer than about six seconds with the
ignition switch in the On position and the engine speed message from the PCM is zero, the trip odometer information will be momentarily
displayed, then the engine hours information will be displayed. The VFD must be displaying the odometer information when the trip odometer
reset switch button is pressed in order to toggle to the engine hours display. The engine hours will remain displayed for about thirty seconds, until
the engine speed message is greater than zero, or until the ignition switch is turned to the Off position, whichever occurs first.
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Trip Odometer Reset - When the trip odometer reset switch button is pressed and held for longer than about two seconds with the ignition
switch in the On or Start positions, the trip odometer will be reset to 0.0 kilometers (miles). The VFD must be displaying the trip odometer
information in order for the trip odometer information to be reset.
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"GASCAP" Message Display - On vehicles manufactured with a United States country code, each time the cluster receives an electronic message
from the PCM indicating a monitored leak in the evaporative emissions system, the cluster replaces the displayed odometer/trip odometer value
with the text message "GASCAP." This message serves as a reminder to the vehicle operator to check that the gas cap is properly installed and
tightened, but could also indicate another source of air leakage in the on-board evaporative and vapor recovery emissions systems. Unless the leak
is corrected, this message will latch and remain displayed during the current and each subsequent ignition cycle until the trip odometer reset button
is pressed and released momentarily, which will revert the display to the odometer/trip odometer information that was last displayed for the
remainder of that ignition cycle. Once the source of a leak has been corrected, either momentarily pressing the trip odometer reset button or
cycling the ignition switch will unlatch the message and return the odometer/trip odometer to normal operation.
